CN103785314A - Mixer and circulating type photometric testing automatic analyzer - Google Patents

Abstract

A mixer and a flow-through photometric detection automatic analyzer are used for the determination of specific components in a solution or the study of chemical reaction kinetics. The lower liquid outlet pipe, one end of the liquid inlet pipe is vertically inserted into the mixture from bottom to top and communicates with its inner cavity, the upper liquid outlet pipe is connected with the top of the mixture body, and the lower liquid outlet pipe is connected with the bottom of the mixture body. The automatic analyzer also includes a mixer, an automatic sampling valve, a reagent selection valve, a three-way valve, a reagent pump, a water sample pump, a multi-channel switching valve, a reagent quantitative loop, a spectroscopic detection device and a control circuit. The photometric detection of the present invention is free from the interference of air bubbles in the flow path, has a high degree of automation, combines automatic sampling and online mixing, does not need to add reagents repeatedly, effectively improves the utilization rate of reagents, and is flexible in operation, and can be adjusted by adjusting the mixing time. Control the degree of reaction and adjust the sensitivity of the instrument to meet the determination requirements of different concentrations of target substances.

Description

A mixer and flow-through automatic analyzer for photometric detection

technical field

The invention relates to a chemical analyzer equipment for spectrophotometric detection, especially a kind of equipment used for the determination of specific components in a solution or the research of chemical reaction kinetics, fully automatic, high accuracy, not affected by bubbles in the flow path, and can realize A mixer with multiple analysis and detection functions and a flow-through automatic analyzer for photometric detection with the mixer.

Background technique

In order to save labor resources and meet the needs of rapid analysis and testing of sample chemical parameters, researchers at home and abroad have developed a variety of automated rapid analysis instruments. In the 1950s, companies such as Technicon in the United States developed an automatic analyzer named Auto-Analyzer based on the bubble interval continuous flow analysis principle proposed by Skeggs, pioneering the transformation of samples, reagents and analysis operations from traditional test tubes and beakers. Waiting for the container to be transferred into the pipeline, promoting the transformation of the solution processing method in chemical analysis. Ruzicka and Hansen first proposed flow injection analysis technology in 1975, which broke the traditional concept that analytical chemical reactions must be completed under physical and chemical equilibrium conditions, and triggered another fundamental change in basic operating techniques in chemical laboratories. Companies such as Lachat Instruments and FIAlab Instruments have successively launched instruments based on flow injection analysis, which are widely used in many fields such as environment, clinical medicine, agriculture, forestry, metallurgical geology, and food. In recent years, the introduction of new analytical technologies and instruments such as sequential injection analysis and laboratory on valve reflects the development of analytical instruments towards miniaturization, integration and automation.

However, there are still some deficiencies in these analytical instruments at present, mainly including: in the bubble interval continuous flow analysis and flow injection analysis, the reagents and samples usually flow continuously, the utilization rate of reagents and samples is low, and the waste is serious ; Existing sequential injection analysis and on-valve laboratory need to use precision syringe pumps, which are expensive and complicated to operate, and it is difficult to completely mix samples and reagents; more importantly, the air bubbles often generated in the flow path have a negative impact on The most commonly used spectrophotometric detection produces severe interference. In environmental monitoring and scientific research, real-time monitoring of target changes, obtaining the true concentration of unstable targets and their changing laws, etc., all require on-site automatic continuous detection systems. However, the deficiencies of existing flow-through analyzers make them unsuitable for on-site long-term automatic and continuous monitoring.

Contents of the invention

The main purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and propose a method for the determination of targets in various water bodies or the research of chemical reaction kinetics, which has less reagent consumption, high accuracy, is not affected by air bubbles, and has Multifunctional mixer and flow-through photometric automatic analyzer.

The present invention adopts following technical scheme:

A mixer used in photometric detection to realize the mixing of reagents and water samples and to eliminate the influence of air bubbles in the flow path on spectrophotometric detection. The liquid outlet pipe and the lower liquid outlet pipe, one end of the liquid inlet pipe is vertically inserted into the mixture from bottom to top and communicated with its inner cavity, the upper liquid outlet pipe is connected to the top of the mixture body, and the lower liquid outlet pipe is connected to the bottom of the mixture body ; The internal diameter of the mixture is large at the top and small at the bottom.

Further, the mixture is a conical mixture.

Further, it also includes a T-shaped tee, one end of which communicates with the bottom of the mixing body, one end communicates with the lower liquid outlet pipe, and one end is inserted into the liquid inlet pipe.

A flow-through automatic analyzer for photometric detection, including a chassis, is characterized in that: it also includes a mixer arranged on the chassis, and an automatic sampling valve, a reagent selection valve, a three-way valve, a reagent pump, a water sample pump, a multi-channel Switching valve, reagent quantitative loop, spectroscopic detection device and control circuit; each water sample inlet of the automatic sampling valve is used to connect each water sample to be tested, and the common channel in the middle is connected to the second connection port of the multi-channel switching valve; The inlet and outlet of the sample pump are respectively connected to the first connection port of the multi-channel switching valve and the liquid inlet pipe of the mixer; the upper liquid outlet pipe of the mixer is directly connected to the first connection port of the three-way valve, and the lower liquid outlet pipe is connected to To the liquid inlet of the spectroscopic detection device, the liquid outlet of the spectroscopic detection device is connected to the second connection port of the three-way valve, and the public port of the three-way valve is connected to the fourth port of the multi-channel switching valve; the third port of the multi-channel switching valve It is used to connect the waste liquid bottle, and the two ends of the reagent quantitative loop are respectively connected to the fifth and eighth ports of the multi-channel switching valve; each reagent inlet of the reagent selection valve is used to connect each reagent bottle, and its common channel and multi-channel switching The seventh port of the valve is connected; the inlet of the reagent pump is connected to the sixth port of the multi-channel switching valve, and the outlet is connected to the waste liquid bottle.

Further, the automatic sampling valve and the reagent selection valve can be four-position, eight-position or sixteen-position selection valves, and the multi-channel switching valve is an eight-way valve.

Further, the spectroscopic detection device includes a light source, a photoelectric detector and a flow cell; the lower outlet pipe of the mixer is connected to the liquid inlet of the flow cell, and the liquid outlet of the flow cell is connected to the second connection port of the three-way valve , the optical inlet and outlet of the flow cell are respectively connected to a light source and a photodetector.

Further, the flow cell is a Z-shaped or U-shaped flow cell with an optical path of 1 cm-15 cm.

Further, the flow cell is a liquid core waveguide long optical path flow cell, the optical path of which is 20cm-1000cm.

Further, the reagent quantitative loop is an annular tube, used to measure and store a fixed volume of reagent, with an inner diameter of 0.25mm-2mm and a length of 3cm-30cm.

Further, the control circuit includes a microprocessor, a peristaltic pump control module, a multi-channel switching valve control module, a multi-position valve control module, a three-way valve control module, a communication module, a data storage module, a light source and a detector module; The pump control module is connected with the reagent pump and the water sample pump; the multi-channel switching valve control module is connected with the multi-channel switching valve; the multi-position valve control module is connected with the automatic sampling valve and the reagent selection valve; the three-way valve The control module is connected with the three-way valve; the light source and the detector module are connected with the spectroscopic detection device; the input terminals of the microprocessor are respectively connected with the communication module, the data storage module, the light source and the detector module; the output of the microprocessor The terminals are respectively connected with the peristaltic pump control module, the multi-channel switching valve control module, the multi-position valve control module, the three-way valve control module and the data storage module.

As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects:

(1) High degree of automation, combined with automatic sampling and online mixing, the entire analysis process does not require human intervention.

(2) The photometric detection of the present invention is not disturbed by air bubbles in the flow path.

(3) The consumption of reagents is very small, and there is no need to add reagents repeatedly, which effectively improves the utilization rate of reagents and saves the amount of reagents used, thus reducing the cost of analysis and testing.

(4) The operation is flexible, and the reaction degree can be controlled by adjusting the mixing time, thereby adjusting the sensitivity of the instrument to meet the determination requirements of different concentrations of target substances.

(5) The sampling speed is fast, and one water sample can be taken to meet the measurement requirements of different forms of targets; and it has good accuracy and precision.

Description of drawings

Fig. 1 a is the structural representation of mixer of the present invention;

Figure 1b is a schematic structural view of Embodiment 1 of the flow-through photometric detection automatic analyzer of the present invention;

Fig. 2 is the composition block diagram of the control circuit of flow-through photometric detection automatic analyzer of the present invention;

Fig. 3 is the schematic diagram of the circuit composition of the control circuit of the flow-through photometric detection automatic analyzer of the present invention;

Fig. 4 is a schematic structural diagram of a flow-through photometric detection automatic analyzer in the sample injection state of the present invention (embodiment 1);

Fig. 5 is a structural schematic diagram of a flow-through photometric detection automatic analyzer in the mixing/detecting state of the present invention (embodiment 1);

Figure 6 is a structural schematic diagram of the present invention using a liquid core waveguide long optical path flow cell and the eight-way valve is in the sample injection state (Example 2, Example 3);

Fig. 7 is a schematic structural diagram of an embodiment of the present invention using a liquid core waveguide long optical path flow cell and an eight-way valve in a mixing/detecting state (Example 2, Example 3);

Fig. 8 is a structural schematic diagram of the present invention equipped with 3 reagent bottles and the eight-way valve is in the sampling state (embodiment 4);

Fig. 9 is a schematic structural diagram of the present invention equipped with 3 reagent bottles and the eight-way valve is in the mixing/detecting state (embodiment 4).

Detailed ways

The present invention will be further described below through specific embodiments.

Referring to Figure 1a, the present invention proposes a mixer for photometric detection to realize the mixing of reagents and water samples and eliminate the influence of air bubbles in the flow path on spectrophotometric detection, including a liquid inlet pipe 1, a T-shaped tee 5, The mixing body 4 and the upper liquid outlet pipe 2 and the lower liquid outlet pipe 3 communicated with the inner cavity of the mixture. One end of the liquid inlet pipe 1 is vertically inserted into the mixing body 4 from bottom to top and communicates with the inner cavity thereof, the upper liquid outlet pipe 2 is connected to the top of the mixing body 4, and the lower liquid outlet pipe 3 is connected to the bottom of the mixing body 4; Body 4 is a conical mixture with a larger inner diameter and a smaller lower diameter. The solid arrows in Figure 1a indicate the flow direction of the solution in the mixed state, and the dashed arrows indicate the flow direction of the solution in the detection state. Both the liquid inlet pipe 1 and the liquid outlet pipe are polytetrafluoroethylene pipes with an inner diameter of 0.75mm and an outer diameter of 1.6mm. The mixture 4 is a cone made of polyethylene, and its two ends have holes with diameters of 8mm and 3mm respectively, and a T-shaped tee 5 made of polyethylene is connected to the thinner end. The liquid inlet pipe 1 extends into the mixture 4 from the bottom through the T-shaped tee 5 until its outlet is 5-10 mm away from the top of the cavity; the top of the mixture 4 is connected to the liquid outlet pipe 2, and the other end of the T-shaped tee 5 is connected to Lower the outlet pipe 3.

When the mixer of the present invention is applied to a photometric detection analyzer, with reference to Fig. 1b, the other end of the upper outlet pipe 2 can be used to connect the three-way valve 14 of the analyzer, and the other end of the lower outlet pipe 3 is then connected to the analyzer's The flow cell 12 is connected to the three-way valve 14 after passing through the flow cell 12 . When performing a mixed reaction operation, the solution in the analyzer pipeline flows into the mixture 4 from the liquid inlet pipe 1, where it undergoes a sudden change in the flow path diameter to realize the mixing of water samples and reagents; switch the three-way valve 14, enter the mixing In the detection state, the solution flowing into the mixture 4 from the liquid inlet pipe 1 can only flow out from the lower liquid outlet pipe 3 and enter the flow cell 12 of the analyzer for spectroscopic detection. At this time, if air bubbles appear in the flow path, the air bubbles will naturally rise under the action of buoyancy and stay on the top of the mixture 4, thereby preventing the air bubbles from entering the flow cell 12 and affecting the spectroscopic detection. The air bubbles that stay on the top of the mixture 4 are removed with the waste liquid when the analyzer is switched to the sample injection state.

The present invention also proposes a flow-through automatic analyzer for photometric detection, which is equipped with the above-mentioned mixer, and several examples are listed below.

Embodiment one

A flow-through automatic analyzer for photometric detection, comprising the above-mentioned mixer, an automatic sampling valve 6, a reagent selection valve 17, a three-way valve 14, a reagent pump 18, a water sample pump 10, a multi-channel switching valve, and a reagent quantitative loop 19 , Spectroscopic detection device and control circuit. Each water sample inlet of the automatic sampling valve 6 is used to connect each water sample to be tested, and the common channel 8 in the middle is connected to the second connection port of the multi-channel switching valve. The inlet and outlet of the water sample pump 10 are respectively connected with the first connection port of the multi-channel switching valve and the liquid inlet pipe 1 of the mixer. The spectroscopic detection device includes a light source 11 , a photodetector 13 and a flow cell 12 . The upper outlet pipe 2 of the mixer is directly connected to the first connection port of the three-way valve 14, the lower outlet pipe 3 of the mixer is connected to the liquid inlet of the flow cell 12, and the liquid outlet of the flow cell 12 is connected to the three-way valve 14 The optical inlet and outlet of the flow cell 12 are connected to the light source 11 and the photodetector 13 respectively. The common interface of the three-way valve 14 is then connected to the fourth interface of the multi-channel switching valve. The third port of the multi-channel switching valve is used as the waste liquid outlet 20 to connect to the waste liquid bottle, and the two ends of the reagent quantitative loop 19 are respectively connected to the fifth and eighth ports of the multi-channel switching valve. Each reagent inlet 15 of the reagent selection valve 17 is used to connect each reagent bottle, and its common channel 16 is connected to the seventh interface of the multi-channel switching valve. The inlet of the reagent pump 18 is connected to the sixth port of the multi-channel switching valve, and the outlet is used as a waste liquid outlet 20 and then connected to a waste liquid bottle.

The flow cell 12 in the present invention adopts a Z-type flow cell. The automatic sampling valve 6 and the reagent selection valve 17 can adopt four-position, eight-position or sixteen-position selector valves, and the present invention adopts eight-position selector valves. The multi-channel switching valve can adopt an eight-way valve 9. The reagent quantitative loop 19 is an annular tube for measuring and storing a fixed volume of reagent, with an inner diameter of 0.25mm-2mm and a length of 3cm-30cm. It can be used for automatic analysis and determination of soluble iron in water by photometric detection in flow-through.

The control circuit is sealed inside the case, and the pump, valve, mixer, reagent bottle (bag) and spectroscopic detection device are also assembled inside the case or fixed on the case shell, and the liquid circulation pipeline and its interface are placed outside the case. Referring to Figure 2 and Figure 3, the specific control circuit includes a microprocessor U1, a peristaltic pump control module, a multi-channel switching valve control module, a multi-position valve control module, a three-way valve control module, a communication module, a data storage module, a light source and detector module. The peristaltic pump control module includes a first power module Q21 and an RS485 interface chip U2 respectively connected to control two peristaltic pumps B21 and B22 (water sample pump 10 and reagent pump 18). The multi-channel switching valve control module is connected with the multi-channel switching valve and includes the second power module Q22 and the third power module Q23, and the signal sent from the microprocessor U1 controls the multi-channel switching through the second power module Q22 and the third power module Q23 Valve switching. The multi-position valve control module is connected with the automatic sampling valve 6 and the reagent selection valve 17, including the RS232 interface chip U3, through which the RS232 interface chip U3 realizes the control of the two multi-position valves P3 and P4 (the automatic sampling valve 6 and the reagent selection valve 17) Control. The three-way valve control module is connected with the three-way valve 14 and includes a fourth power module Q24, and a signal is sent from the microprocessor U1 to control switching of the three-way valve 14 (P5 in FIG. 3 ) through the fourth power module Q24. The communication module is composed of USB interface P1, through which the communication between the instrument and the outside world is realized. The data storage module is composed of 2GTF card memory U4, which is used to store detection data. The light source and detector module consists of a photodetector 13 (chip U5), a constant current source U6 and a light emitting diode (L1). The photodetector 13 detects changes in light intensity and outputs square waves of different frequencies to the microprocessor U1. A light emitting diode with an emission wavelength of 558nm is used as the light source 11, driven by a constant current source U6. The microprocessor U1 also has a built-in program memory, which is used to store the control program of the instrument. The input terminals of the microprocessor U1 are respectively connected with the communication module, the data storage module, the light source and the detector module. The output end of the microprocessor U1 is respectively connected with the peristaltic pump control module, the multi-channel switching valve control module, the multi-position valve control module, the three-way valve control module and the data storage module. The code, reference model and parameters of each device and original part are as follows: U1—microprocessor STM32F103VBT6; U2—RS485 interface chip SP3485; U3—RS232 interface chip MAX3232; U4—Kingston2GTF card memory; U5—programmable light Frequency converter TSL230RD; Q21, Q22, Q23, Q24——first to fourth power module IRFM210A; P1——USB communication port mini-USB-B; B21——Baoding Lange peristaltic pump OEMBJ60-01/WX10; B22 ——Baoding Lange peristaltic pump BT100-2J; P2——eight-way valve C22Z-3188EH; P3, P4——multi-position selection valve C25Z-3188EMH; P5——three-way valve 100T3MP12-62.

The eight-position selector valve is used as the automatic sampling valve 6, and each water sample inlet 7 thereof is respectively connected to each water sample to be tested or a standard solution, so as to automatically select the water sample to be tested. Before the measurement, the water sample was directly acidified with hydrochloric acid to a pH value of about 1.7 without filtration, and stored for 24 hours. According to this pretreatment, the measured total soluble iron, including dissolved and part of granular iron.

The reagents used are mainly phenanthrolazine solution and ascorbic acid solution, which are respectively contained in the reagent bottle 22 of the developer and the reagent bottle 23 of the reducing agent. Among them, the concentration of phenanthrozine solution is 0.01mol/L, and it is prepared in acetic acid-ammonium acetate buffer solution with a pH value of 5.5. It can undergo complexation and color reaction with Fe(II), and the color development product is at 562nm wavelength. It has the maximum absorption; the concentration of ascorbic acid solution is 0.001mol/L, which is used to reduce Fe(III) in water samples to Fe(II) to determine the concentration of total soluble iron in water samples.

When measuring water samples, the analyzer is first in the sampling state shown in Figure 4, that is, the eight-way valve is switched to connect the first port and the second port, the third port and the fourth port, the fifth port and the sixth port, and the seventh port and the eighth interface. Start the water sample pump 10 to pump the sample to be tested into the analyzer through the water sample inlet 7, and switch the three-way valve 14 to make the water sample fill the entire pipeline, the mixture 4 and the Z-shaped flow cell 12, and the excess water sample Discharged through the waste liquid outlet 20, the photoelectric detector 13 records the light intensity at this time as the blank light intensity and adjusts the absorbance to zero; at the same time, switch the valve position of the reagent selection valve 17, connect to the chromogen reagent bottle 22, and start The reagent pump 18 pumps the phenanthrozine solution into the analyzer and fills the reagent quantitative loop 19 , and the excess reagent is discharged through the waste liquid outlet 20 . Switch the eight-way valve 9 so that the analyzer is in the mixing/detection state shown in Figure 5, that is, connect the first port and the eighth port, the second port and the third port, the fourth port and the fifth port, the sixth port and the Seven interfaces. The three-way valve 14 is connected to the liquid outlet pipe 2 on the mixer, and the water sample pump 10 is started to drive the water sample to mix with the chromogen, so that the Fe(II) in the water sample reacts with phenanthrozine to generate a purple-red complex. compound. After 60 seconds of mixed reaction, stop the water sample pump 10, switch the eight-way valve 9, make the analyzer return to the sampling state shown in Figure 4, switch the valve position of the reagent selection valve 17, connect to the reducing agent reagent bottle 23, and start the reagent pump 18 Pump the ascorbic acid solution into the analyzer and fill the reagent quantitative loop 19, and the excess reagent is discharged through the waste liquid outlet 20. Switch the eight-way valve 9, the analyzer is in the mixing/detection state shown in Figure 5, the three-way valve 14 is connected to the outlet pipe 2 on the mixer, and the water sample pump 10 is started to drive the sample to mix with ascorbic acid, then Fe(III) is reduced into Fe(II) and a color reaction occurs with phenanthrenoxazine; after the mixed reaction for 120s, switch the three-way valve 14 to allow the sample to flow into the Z-type flow cell 12 from the liquid outlet pipe 3 under the mixer, and record the test result by the photoelectric detector 13. The absorbance of the sample is then substituted into the standard working curve equation to calculate the concentration of total soluble iron in the water sample.

The linear equation of the obtained working curve is A= _0.0223CFe -0.0082 (R ² =0.9988), where A is the absorbance recorded by the photodetector 13, _CFe is the concentration of soluble total iron, the unit is μmol/L, and the linear range Between 0.10μmol/L-45μmol/L. The concentration of soluble total iron in the surface water of the Jiulong River Estuary was measured by this instrument and compared with the concentration measured by the conventional manual reagent addition colorimetric method. The results are listed in Table 1. Fit the linear relationship between the two to get y=0.9791x+0.0585 (R ² =0.9940), where y is the concentration measured by the analyzer, and x is the concentration measured by the conventional colorimetric method. It can be seen that the analyzer The detection results were in good agreement with conventional colorimetric methods.

Table 1 Analyzer of the present invention compares with the result comparison of conventional colorimetric method measuring soluble state total iron in water

Embodiment two

Flow-through Photometric Automatic Chemical Analyzer Using Liquid Core Waveguide Long Optical Path Flow Cell and Simultaneous Determination of Dissolved Trace Fe(II) and Fe(II+III) in Water

As shown in Figure 6 and Figure 7, in addition to replacing the Z-shaped flow cell in Embodiment 1 with a liquid core waveguide long optical path flow cell 12 with an optical path length of 250 cm, the instrument components, pipeline connections, control The circuit, the reagents used and their concentrations are consistent with those in Example 1.

When measuring water samples, the analyzer is first in the sampling state shown in Figure 6, and connects the first interface and the second interface, the third interface and the fourth interface, the fifth interface and the sixth interface, and the seventh interface and the eighth interface. Start the water sample pump 10 to pump the sample to be tested into the analyzer through the water sample inlet 7, and by switching the three-way valve 14, the water sample is filled with the entire pipeline, the mixture 4 and the liquid core waveguide long optical path flow cell 12. The water sample is discharged through the waste liquid outlet 20, and the photoelectric detector 13 records the light intensity at this time as the blank light intensity and adjusts the absorbance to be zero; at the same time, switch the valve position of the reagent selection valve 17, and connect to the reagent bottle of the chromogenic agent. 22. Start the reagent pump 18 to pump the phenanthrozine solution into the analyzer and fill the reagent loop 19, and the excess reagent is discharged through the waste liquid outlet 20. Switch the eight-way valve 9 so that the analyzer is in the mixing/detection state shown in Figure 7. The three-way valve 14 is connected to the liquid outlet pipe 2 on the mixer, and the water sample pump 10 is started to drive the water sample to mix with the chromogen to make the water sample Fe(II) reacts with phenanthrazine to form a purple complex. After mixing and reacting for 60 seconds, switch the three-way valve 14 to allow the sample to flow into the liquid core waveguide long optical path flow cell 12 from the liquid outlet pipe 3 under the mixer. At this time, what the photoelectric detector 13 records is the Fe(II) in the water sample. Absorbance after coloring.

Stop the water sample pump 10, switch the three-way valve 14 and the eight-way valve 9, make the analyzer return to the sampling state of Figure 6, switch the valve position of the reagent selection valve 17, connect to the reducing agent reagent bottle 23, and start the reagent pump 18 Pump the ascorbic acid solution into the analyzer and fill the reagent quantitative loop 19, and the excess reagent is discharged through the waste liquid outlet 20. Switch the eight-way valve 9, and the analyzer is in the mixing/detection state shown in Figure 7, that is, connecting the first port and the eighth port, the second port and the third port, the fourth port and the fifth port, the sixth port and the seventh port interface. The three-way valve 14 is connected to the liquid outlet pipe 2 on the mixer, and the water sample pump 10 is started to drive the sample to mix with ascorbic acid, so that Fe(III) is reduced to Fe(II) and reacts with phenanthrolizine; mixing reaction After 120s, switch the three-way valve 14 to make the sample flow into the liquid core waveguide long optical path flow cell 12 from the liquid outlet pipe 3 under the mixer. At this time, the absorbance recorded by the photodetector 13 includes The obtained Fe(II) and the original Fe(II) are Fe(II+III). The concentration of Fe(II) and Fe(II+III) in the water sample can be calculated by substituting the obtained absorbance of Fe(II) and Fe(II+III) after color development into the corresponding standard working curve equation.

The linear equations of the working curves of Fe(II) and Fe(II+III) are A=0.0065C _Fe(II) +0.0546 (R ² =0.9993) and A=0.0057C _Fe(II+III) +0.0464 (R ² =0.9989), where A is the absorbance recorded by the photodetector 13, C _Fe(II) and C _Fe(II+III) are the concentrations of Fe(II) and Fe(II+III) respectively, in nmol/L, The linear ranges are 0.5nmol/L-145nmol/L and 0.5nmol/L-165nmol/L, respectively. The analyzer was used to measure water samples collected from the South China Sea and the Jiulong River Estuary, which were filtered through a 0.4 μm filter membrane and acidified to pH 1.7, and compared with the existing long optical path colorimetric method with manual addition of reagents. The results are listed in the table 2. Fitting the linear relationship between the two, the linear relationship of dissolved trace Fe(II) is y=0.9969x+0.0180 (R ² =0.9913), and the linear relationship of dissolved trace Fe(II+III) is y= 0.9923x+0.0167 (R ² =0.9992), where y is the concentration measured by the analyzer, and x is the concentration measured by manual colorimetry. It can be seen that for dissolved trace Fe(II) and Fe(II+III), the detection results of this analyzer are in good agreement with the manual colorimetric method. In addition, this analyzer is also used to determine the seawater standard reference samples CASS-4 and NASS-5 provided by the National Research Council of Canada. The results obtained are listed in Table 3. The results measured by this analyzer are within the reference value range and have good accuracy.

Table 2 Analyzer of the present invention compares with the result of existing method measurement dissolved state trace Fe(II) and Fe(II+III) in water

Table 3 Analyzer of the present invention measures the result of seawater standard reference sample

Embodiment Three

Flow-through photometric detection automatic chemical analyzer using liquid core waveguide long optical path flow cell and determination of trace nitrite in seawater

As shown in Figures 6 and 7, the instrument parts, pipeline connections, control circuit and flow cell 12 of this embodiment are all consistent with the second embodiment, except that the reagents in the chromogenic reagent bottle 22 and the reducing reagent bottle 23 are Replace the sulfonamide solution with a concentration of 6.4g/L and the naphthaleneethylenediamine hydrochloride solution with a concentration of 0.72g/L respectively, wherein the sulfonamide solution is prepared in a hydrochloric acid solution of 1.4mol/L; led.

The operation steps of this embodiment are consistent with Embodiment 1, that is, the analyzer is first in the sample feeding state of Fig. 6, and the water sample pump 10 is started to pump the sample to be tested into the analyzer through the water sample inlet 7, and by switching the three-way valve 14. Make the water sample fill the entire pipeline, the mixture 4 and the liquid core waveguide long optical path flow cell 12, and the excess water sample is discharged through the waste liquid outlet 20, and the photoelectric detector 13 records the light intensity at this time as the blank light intensity and Adjust the absorbance to be zero; at the same time, switch the valve position of the reagent selection valve 17, be connected to the chromogenic reagent bottle 22, start the reagent pump 18 and pump the sulfonamide solution into the analyzer and be full of the reagent quantitative loop 19, and the excess reagent is passed through the waste liquid Exit 20 discharges. Switch the eight-way valve 9 to make the analyzer in the mixing/detection state shown in Figure 7, connect the three-way valve 14 to the outlet pipe 2 on the mixer, and start the water sample pump 10 to drive the water sample to mix with the sulfonamide solution. After 60s, stop the water sample pump 10, switch the eight-way valve 9, make the analyzer get back to the sampling state of Fig. 6, switch the valve position of the reagent selection valve 17, be connected to the reducing reagent bottle 23, start the reagent pump 18 to convert the naphthalene hydrochloride The ethylenediamine solution is pumped into the analyzer and fills the reagent quantitative loop 19, and the excess solution is discharged through the waste liquid outlet 20. Switch the eight-way valve 9, the analyzer is in the mixing/detection state of Figure 7, the three-way valve 14 is connected to the liquid outlet pipe 2 on the mixer, and the water sample pump 10 is started to drive the sample to mix with the naphthaleneethylenediamine hydrochloride solution; after 120s , switch the three-way valve 14 to make the sample flow into the liquid core waveguide long optical path flow cell 12 from the liquid outlet pipe 3 under the mixer, record the absorbance of the sample through the photodetector 13, and then substitute it into the standard working curve equation for calculation, then it can be determined The concentration of nitrite in the water sample.

The linear equation of the obtained working curve is A=0.0127C _NO2 +0.0709 (R ² =0.9996), where A is the absorbance recorded by the photodetector 13, C _NO2 is the concentration of nitrite, the unit is nmol/L, and the linear range is 0.6 Between nmol/L-85nmol/L. The analyzer was used to measure the concentration of nitrite in seawater samples from the South China Sea, and compared with the concentration measured by the long optical path colorimetric method with manual addition of reagents. The results are listed in Table 4. Fitting the linear relationship between the two results in y=1.0102x-0.0063 (R ² =0.9984), where y is the concentration measured by the analyzer, and x is the concentration measured by the manual reagent colorimetric method. The detection results of the analyzer are in good agreement with the conventional manual colorimetric method.

Table 4 Analyzer of the present invention and reference method measure the result comparison of trace nitrite in seawater

Embodiment Four

Flow-through photometric detection automatic chemical analyzer using U-shaped flow cell and determination of active silicate in seawater

As shown in Figure 8 and Figure 9, compared with Embodiment 3, the spectroscopic detection system of this embodiment adopts a U-shaped flow cell 12 with an optical path of 5 cm and a light-emitting diode with an emission wavelength of 810 nm as the light source 11, and the reagent selection valve The reagent inlet 15 on the 17 connects a reagent bottle 24 more. Three reagent bottles 22, 23 and 24 are respectively filled with a mixed solution of 32g/L ammonium molybdate-2% sulfuric acid, 100g/L tartaric acid solution and 10g/L ascorbic acid solution.

When measuring water samples, the analyzer is first in the sampling state shown in Figure 8, that is, the eight-way valve is switched to connect the first port and the second port, the third port and the fourth port, the fifth port and the sixth port, and the seventh port and the eighth interface. Start the water sample pump 10 to pump the sample to be tested into the analyzer through the water sample inlet 7, and by switching the three-way valve 14, the water sample is filled with the entire pipeline, the mixture 4 and the U-shaped flow cell 12, and the excess water sample is passed through The waste liquid outlet 20 is discharged, and the photoelectric detector 13 records the light intensity at this time as the blank light intensity and adjusts the absorbance to be zero; at the same time, switch the valve position of the reagent selection valve 17, connect it to the reagent bottle 22, and start the reagent pump 18. The ammonium molybdate-sulfuric acid mixed solution is pumped into the analyzer and filled with the reagent quantitative loop 19, and the excess reagent is discharged through the waste liquid outlet 20. Switch the eight-way valve 9 so that the analyzer is in the mixing/detection state shown in Figure 9, that is, connect the first port and the eighth port, the second port and the third port, the fourth port and the fifth port, the sixth port and the Seven interfaces. The three-way valve 14 is connected to the outlet pipe 2 on the mixer, and the water sample pump 10 is started to drive the water sample to mix with the ammonium molybdate-sulfuric acid mixed solution. The active silicate in the water sample reacts with the ammonium molybdate to generate Yellow silicon molybdenum heteropolyacid. After mixed reaction 60s, stop water sample pump 10, switch eight-way valve 9, make analyzer get back to the sampling state of Fig. 8, switch the valve position of reagent selection valve 17, be connected to reagent bottle 23, start reagent pump 18 to put The solution is pumped into the analyzer and fills the reagent quantitative loop 19, and the excess reagent is discharged through the waste liquid outlet 20. Switch the eight-way valve 9, the analyzer is in the mixing/detection state shown in Figure 9, the three-way valve 14 is connected to the liquid outlet pipe 2 on the mixer, and the water sample pump 10 is started to drive the sample to mix with the tartaric acid solution to eliminate the interference of phosphate . After the mixed reaction for 60s, stop the water sample pump 10, switch the eight-way valve 9, and make the analyzer return to the sampling state of Fig. 8 again, switch the valve position of the reagent selection valve 17, connect it to the reagent 24, and start the reagent pump 18 to convert the ascorbic acid The solution is pumped into the analyzer and fills the reagent quantitative loop 19, and the excess reagent is discharged through the waste liquid outlet 20. Switch the eight-way valve 9, the analyzer is in the mixing/detection state shown in Figure 9, the three-way valve 14 is connected to the outlet pipe 2 on the mixer, and the water sample pump 10 is started to drive the sample to mix with the ascorbic acid solution, and the yellow silica in the sample Molybdenum heteropolyacid is reduced to blue silicon-molybdenum heteropolyacid; after the mixing reaction for 90s, switch the three-way valve 14 to make the sample flow into the U-shaped flow cell 12 from the liquid outlet pipe 3 under the mixer, and record it through the photoelectric detector 13. The absorbance of the sample is then substituted into the standard working curve equation to calculate the concentration of active silicate in the water sample.

The linear equation of the obtained working curve is A=0.0133C _Si -0.0156 (R ² =0.9994), where A is the absorbance recorded by the photodetector 13, C _Si is the concentration of active silicate, the unit is μmol/L, and the linear range is Between 0.2μmol/L-80μmol/L. The concentration of active silicate in the seawater of the South China Sea and the surface water of the Kowloon River estuary was measured by this instrument and compared with the concentration measured by the conventional colorimetric method of manually adding reagents. The results are listed in Table 5. Fit the linear relationship between the two to get y=0.9933x-1.0814 (R ² =0.9950), where y is the concentration measured by the analyzer, and x is the concentration measured by the conventional colorimetric method. It can be seen that the analyzer The detection results were in good agreement with conventional colorimetric methods.

Table 5 Analyzer of the present invention compares with the result comparison of routine manual colorimetry measuring active silicate in seawater

The analyzer in this embodiment can also be used for the determination of ammonia nitrogen in water by the hypobromite oxidation method or the indophenol blue spectrophotometric method. For the determination of other target objects that need to add more reagents, only the required reagents need to be connected to the reagent inlet 15 of the reagent selection valve 17, and the mixed reaction is added in order to develop color, and at the same time, it is replaced according to the maximum absorption wavelength of the target object after color development. The corresponding light-emitting diode can complete the determination of the target object.

The above is only a specific embodiment of the present invention, but the design concept of the present invention is not limited thereto, and any non-substantial changes made to the present invention by using this concept should be an act of violating the protection scope of the present invention.

Claims (10)

1. a blender, realize the mixing of reagent and water sample and eliminate the impact on spectrophotomelric assay of bubble in stream for photometric detection, it is characterized in that: comprise feed tube, mixture and the upper drain pipe being communicated with mixture inner chamber and lower drain pipe, this feed tube one end is from bottom to top vertically inserted mixture and is communicated with its inner chamber, on this, drain pipe is connected with mixture top, and this lower drain pipe is connected with mixture bottom; This mixture internal diameter is up big and down small.

2. a kind of blender as claimed in claim 1, is characterized in that: described mixture is conical mixture.

3. a kind of blender as claimed in claim 1, is characterized in that: also comprise T-shaped threeway, its one end is communicated with described mixture bottom, and one end is communicated with lower drain pipe, and insert for described feed tube one end.

4. a flow type photometric detection automated analysis instrument, comprise cabinet, it is characterized in that: also comprise any blender described in the claims 1 to 3 being arranged on cabinet, and automatic sampling valve, reagent selector valve, triple valve, reagent pump, water sample pump, Multi-channel switching valve, reagent quantitative ring, point optical detection device and control circuit; Each water sample entrance of automatic sampling valve is respectively used to connect each water sample to be measured, and middle public passage is connected with the second connector of Multi-channel switching valve; The entrance and exit of water sample pump is connected with the first connector of Multi-channel switching valve and the feed tube of blender respectively; The upper drain pipe of blender is directly connected to the first connector of triple valve, lower drain pipe is connected to the liquid inlet of point optical detection device, divide the liquid outlet of optical detection device to be connected to the second connector of triple valve, the common interface of triple valve is connected to the 4th interface of Multi-channel switching valve again; The 3rd interface of Multi-channel switching valve is used for connecting waste liquid bottle, and the two ends of reagent quantitative ring are connected with the 5th, the 8th interface of Multi-channel switching valve respectively; Each reagent entrance of reagent selector valve is respectively used to connect each reagent bottle, and its public passage is connected with the 7th interface of Multi-channel switching valve; The entrance of reagent pump is connected to the 6th interface of Multi-channel switching valve, and outlet is connected to waste liquid bottle again.

5. a kind of flow type photometric detection automated analysis instrument as claimed in claim 4, is characterized in that: described automatic sampling valve and described reagent selector valve can adopt four, eight or sixteen bit selector valve, and described Multi-channel switching valve adopts eight logical valves.

6. a kind of flow type photometric detection automated analysis instrument as claimed in claim 4, is characterized in that: described point of optical detection device comprises light source, photoelectric detector and flow cell; The lower drain pipe of described blender is connected to the liquid inlet of flow cell, and the liquid outlet of flow cell is connected to the second connector of triple valve, and the optics entrance and exit of described flow cell is connected to respectively light source and photoelectric detector.

7. a kind of flow type photometric detection automated analysis instrument as claimed in claim 6, is characterized in that: described flow cell is Z-type or U-shaped flow cell, and its light path is 1cm-15cm.

8. a kind of flow type photometric detection automated analysis instrument as claimed in claim 6, is characterized in that: described flow cell is the long light path flow cell of liquid core waveguide, and its light path is 20cm-1000cm.

9. a kind of flow type photometric detection automated analysis instrument as claimed in claim 4, is characterized in that: described reagent quantitative ring is ring pipe, and for measuring and store the reagent of fixed volume, its internal diameter is 0.25mm-2mm, and length is 3cm-30cm.

10. a kind of flow type photometric detection automated analysis instrument as claimed in claim 4, is characterized in that: described control circuit comprises microprocessor, peristaltic pump control module, Multi-channel switching valve control module, multiposition valve control module, triple valve control module, communication module, data memory module, light source and detector module; Peristaltic pump control module is connected with water sample pump with described reagent pump; Multi-channel switching valve control module is connected with described Multi-channel switching valve, and multiposition valve control module is connected with reagent selector valve with described automatic sampling valve, and triple valve control module is connected with described triple valve; Light source is connected with described point of optical detection device with detector module; The input of microprocessor is connected with communication module, data memory module, light source and detector module respectively; The output of microprocessor is connected with peristaltic pump control module, Multi-channel switching valve control module, multiposition valve control module, triple valve control module and data memory module respectively.

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